NASA's Jupiter-circling spacecraft is stuck making long laps around the gas giant because of sticky valves. It currently takes Juno 53 days to fly around the solar system's biggest planet. That's almost four times longer than the intended 14-day orbit. After repeated delays, NASA decided late last week to forgo an engine firing that would have shortened the orbit. Officials said the maneuver posed too much risk. NASA said the quality of science won't be affected, but it will take more time to gather the data, given Juno's longer loops. The mission will have to be extended at tens of millions of extra dollars if scientists are to collect everything called for under the original plan. It's already a $1 billion mission. Juno has been circling Jupiter since July.